Rust bare metal on ARM microcontroller

http://antoinealb.net/programming/2015/05/01/rust-on-arm-microcontroller.html

by AndrewDucker • 11 years ago

80 20 11 years ago

We've been actively working on stabilizing #![no_std], as well as making cross-compilation easier. In the future, ideally, you'll just need

    $ cargo build --target thumbv7em-none-eabi

instead of

    $ rustc -C opt-level=2 -Z no-landing-pads --target thumbv7em-none-eabi -g --emit obj -L libcore-thumbv7m -o runtime.o runtime.rs

or other shenanigans. You can run that Cargo command right now, but you still need to do a little bit of work first.

antoinealb5• 11 years ago

Nice! Any pointer to a documentation / wiki explaining how to use it ?

steveklabnik2• 11 years ago

"it" being --target? https://github.com/rust-lang/rfcs/blob/master/text/0131-targ... is the original RFC. Off the top of my head, I think that's it for now. Since cross compilation is getting easier in the future, I haven't invested a lot of time into writing docs now.

Animats• 11 years ago

Very nice. When this gets cleaned up, and Rust stabilizes a bit more, it should be promoted for the Arduino Due. The Due is a minimal ARM machine, a step up from the Atmel CPUs but well below the level required to run Linux.

Safety at the Rust level is very valuable in embedded work. Debugging small embedded machines is not fun.

petra3• 11 years ago

I agree. I wonder though - why all the rust projects go bare metal, instead of integrating a c based RTOS using rustbingen ? Seems like the fastest way to get cross-platform, which is key for many developers - and speed rust's adoption - making bare metal much easier.

LBarret• 11 years ago

I think rust people wants to proove repeatedly the addded value of their language : "no cost abstraction over bare metal" because it is the thing that will win the heart of their audience. Still, in practice, it will likely play as you say, but not now.

rcxdude• 11 years ago

Hooking into an RTOS doesn't really give you much cross-platform ability: most RTOS only give you a scheduler and synchronisation primitives, not any drivers. The closest thing to a a cross-platform RTOS I know of is chibiOS, and it supports a fairly low number of platforms.

antoinealb5• 11 years ago

author here. My RTOS of choice (ChibiOS) uses a lot of function like macros which are not supported by rustbindgen. Other RTOSes such as FreeRTOS or UC/OS-II would be easier but they don't provide drivers, making them less interesting.

If anybody has experience with writing C macros to rust bindings I would be interested in hearing about it.

elcritch3• 11 years ago

A C based rtos inherits all the difficulties present in C. Ideally Rust is interesting, to me, as an ideal language to write the RTOS itself in. Once you get through the low level details, writing a (simple) schedule system is not hard and would be more flexible due to the better types safety in Rust. Also C is difficult for DSLs, Rust should be better. That's the dream at least.

antoinealb5• 11 years ago

In my opinion Arduino Due are overrated. They are pricey, their processor isn't really top-tier and you don't get a builtin JTAG probe for debugging (I think).

You should try ST's discovery/nucleo boards. Much cheaper and ChibiOS (www.chibios.org) has some nice API and examples to get started.

elcritch3• 11 years ago

Handy to know; thanks for the heads up!

andars2• 11 years ago

Rust does look promising for embedded applications. Ideally, I'd like to be able to use it to program Pebble applications. I managed to get a simple executable written in rust to write to the screen a few months ago, but haven't been able to get even slightly more complex things to work. Hopefully the hard work of rust devs will make this easier in the future.

CyberDildonics• 11 years ago

How would they make it easier?

andars2• 11 years ago

Erm, see steveklabnik's comment on this story. It is sort of a complex process right now in that you have to build libcore yourself and then try to link everything together (for me, that mostly involves trying something and then crossing my fingers, because my knowledge of that level of tooling is limited). I've heard several times that rust devs are hoping to make cross compilation easier.

alnsn• 11 years ago

This is going to be interesting. Rust on top of rumprun bare-metal unikernel https://twitter.com/gandro23/status/645734117699624960

Rust bare metal on ARM microcontroller

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